Airplane propeller



April 19, 1932 FORTENER 1,854,611

AIRPLANE PROPELLER Fi led Nov. 19, 1950 II I ll 1 fliilililiiiw'.

Patented Apr. 19, 1932 PATENT 0F ANTHONY B. FORTENER, OF DAYTON, OHIO'AIRPLA-NE PROPELLEB Application filed November 19, 1930. Serial No.496,716.

invention relates to propellers and more particularly to a helical orscrew type propeller for use upon airplanes and which is especiallyadapted for use upon airplanes of the helicopter type, and upondirigible airships but which may be applied to other purposes.

The present propeller comprises a double helix .of relatively largediameter and'small pitch affording between the turns of the helix twosemicircular passages having their intake orifices at one side of thepropeller and theirdischarge or outletopenings at the opposite thereof.

At thedischarge or outlet end of each passage there is hinged a closureflap which is free to swing to and fro .to open and close thecorresponding passage. During the normal operation of the propeller thisflap is extended in open position wherein it is substantially alignedwith, and forms a continuationof the wall of the propeller passage towanna is hinged. t is limited in its outward or opening movement tosuchaligned relation by a stop flange which overhangs the'hingejointof-the closure flap and against which the flap abuts when open.Upon reverse movement of the propeller or upon descent ofmachine, in theevent it is used upon a helicopter type of plane, theclosure willautomatically swing to a reverse position across the outlet from thepropeller thereby closing the air passagesand ineffect-transformingthepropeller into a circular wing or air baffle.

The object of the invention is to simplify the constructionas well asthe mode of opera- .tion of aerial propellers whereby they will not onlybe cheapened in construction but will be more eticient in use, capableof exerting maximum propelling effect and un likely toget out of order.

A further object of the invention is taprovide-a closure forthe spaceintermediate the vanes of the propeller whereby the propeller may betransformed into a supporting wing or baflle.

A further object of the invention is to provide a propeller havingautomatically adjustable means for varying the effect of the device.

With the above primary and other incidental objects in view as will morefully appear in the specification, the invention consists of thefeatures of construction, the parts and combinations thereof, and themode of operation, or their equivalents as hereinafter described and setforth in the claims.

Referring to the accompanying drawings wherein is shown the preferredbut obviously not necessarily the only forms of embodiment oftheinvention, Fig. l, is a side elevation of the assembled helicalpropeller forming the-subject matter hereof. Fig. 2isasimilar View with,a portion of the peripheral wall removedon line 22 of Fig.3. Fig. 3 is"a side elevation of the outlet or discharge side of .thepropeller. Fig.4 is a detail sectional view illustrating the mounting and range ofmovement of the closure flap.

Like parts are indicated by similar characters of reference throughoutthe several views.

W'hilejthe present propeller may be made of any suitable ordesireddiameterand the vanes and intermediate.airpassagcsmay be given anydesired pitch, the diameter will nevertheless be comparatively large inproportion-to thepitch or axial extent of the 1 propeller.

Referring to the drawings 1 is a propeller shaft-on which is. carriedthe hub or head 2, which to reduce resistance .to air pressure ispreferably of conoidalfor n. -Secured to the head2, are two helical disclike vanes spaced one from the other tov afford two semicircularairpassages 4 and 5. The vanes 3 are in effectdiscs of sheet metal whichare radially slit from their periphery to their center, each on a singleradial line, theportions adjacent to the slit beinga'laterally'displacedrelative to each other into 'helical formation. The twohelicaldiscs-arefixedly attached in spaced relation'to'thehub 2..thjusforming-a double helix or screw consisting of one complete :turn. 'Thevanes-*3 are peripherallyinterconnected by an annular .wallfitwhichconfines the .airfcurrents-to the passages l and 5. The respectivewages-.3

are of like extent but are rotated relative to each other so that thevanes start and terminate on diametrically opposite radial lines.

Thus the intervening air space 4; has its in-' take orifice at i on oneside of the supporting hub 2 and its discharge orifice at thediametrically opposite side of the hub, and on the opposite side of thestructure as indicated by the arrow 4?. Likewise the second air spaceintermediate the vanes 3 has its intake orifice at the side of the hub 2opposite that observed in Figs. 1 and 2 as indicated at 5 and itsdischarge orifice is on the adjacent side of the hub as indicated at 5Hinged to the wall of each air passage 4 and 5 at the outlet orifices 4:and 5* thereof is a variable closure flap 6. During the normal operationof the propeller this closure flap is extended in substantially parallelalignment with the side wall of the air passage to which it is hinged.It is held to this position by the current of air flowing through thecorresponding air passage as the propeller rotates. Its swingingmovement is limited in its outward or opening direction by anoverlapping stop flange 7 upon the supporting wall of the air passagewhich stop flange projects beyond the hinge 8 and affords an abutmentfor the swinging closure flap 6 when extended. Upon the reversal of theair current the closure flap will automatically swing into contact withthe vane 3 beyond the outlet from the air passage as shown by dottedlines and will close the passage. The propeller is thus transformed intoan air bafile or wing affording resistance to air pressure.

The construction while simple and ineX- pensive, materially increasesthe efficiency of rotary propellers for aerial purposes and by enablingthe automatic conversion of the propeller into a supporting surface, itmaterially increases the safety of aerial navigation.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the parti cularfeatures of advantage before enumere ated desirable. but which obviouslyis susceptible of modification in its form, proportions, detailconstruction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limitedto the specificfeatures shown, but that the means and construction herein disclosedcomprise the preferred form of several modes of putting the inventioninto effect and the invention is therefore claimed in any of its formsor modification within the legitimate and valid scope of the appendedclaims.

Having thus described my invention, I claim:

1. An airplane propeller comprising two discs of helical contour spacedone from the other and connected peripherally to form therebetween twohelical passages of semicircular extent having inlet openings at oneside ofthe propeller and outlet openings at the opposite side thereofand closure flaps hinged to said discs adjacent the outlet openings andadapted to swing into and out of position to close the openings.

2. An air propeller comprising a helical disc having therein twoindependent air passages, each extending throughout one half thecircumference of the disc and each having an entrance on one side of thedisc and an outlet on the opposite side of the disc, and closure flapshinged to the disc contiguous to the outlets from the passages andswinging into and out of contact with the disc to close and open thepassages.

3. An air propeller comprising a helical disc having therein twoindependent air passages, each extending throughout one half thecircumference of the disc and each having an entrance on one side of thedisc and an outlet on the opposite side of the disc, and closure meansfor the air passages.

I. In an airplane propeller a plurality of helically disposed propellerblades and flaps hinged to the trailing edges of the blades adapted toswing into contact with adjacent blades to afford a continuous airbaffle.

5. In an airplane propeller a rotary disc having therethrough twoindependent helical passages and closures for the outlets of saidpassages adapted to be operated by air pressure.

6. In an airplane propeller a screw propeller having multiple helicalblades affording therebetween separate helical channels, and closuremeans for each of the channels. 7. In an airplane propeller rotaryspaced blades inclined to the plane of rotation and movable closure forthe space intermediate the blades.

8. In an airplane propeller, a disc having a helical passagetherethrough and a closure for the outlet from said passage.

9. In an airplane propeller a screw propeller of relatively largediameter and short pitch, the space between succeeding turns beingperipherally enclosed, and a variable closure for the outlet from saidspace.

In testimony whereof, I have hereunto set my hand this 18th day ofNovember, A. D.

ANTHONY B. FORTENER.

